/*
SHA-1 in C
By Steve Reid <sreid@sea-to-sky.net>
100% Public Domain

-----------------
Modified 7/98
By James H. Brown <jbrown@burgoyne.com>
Still 100% Public Domain

Corrected a problem which generated improper hash values on 16 bit machines
Routine SHA1Update changed from
    void SHA1Update(SHA1_CTX* ctx, dduint8* data, unsigned int
len)
to
    void SHA1Update(SHA1_CTX* ctx, dduint8* data, unsigned
long len)

The 'len' parameter was declared an int which works fine on 32 bit machines.
However, on 16 bit machines an int is too small for the shifts being done
against
it.  This caused the hash function to generate incorrect values if len was
greater than 8191 (8K - 1) due to the 'len << 3' on line 3 of SHA1Update().

Since the file IO in main() reads 16K at a time, any file 8K or larger would
be guaranteed to generate the wrong hash (e.g. Test Vector #3, a million
"a"s).

I also changed the declaration of variables i & j in SHA1Update to
unsigned long from unsigned int for the same reason.

These changes should make no difference to any 32 bit implementations since
an
int and a long are the same size in those environments.

--
I also corrected a few compiler warnings generated by Borland C.
1. Added #include <process.h> for exit() prototype
2. Removed unused variable 'j' in SHA1Final
3. Changed exit(0) to return(0) at end of main.

ALL changes I made can be located by searching for comments containing 'JHB'
-----------------
Modified 8/98
By Steve Reid <sreid@sea-to-sky.net>
Still 100% public domain

1- Removed #include <process.h> and used return() instead of exit()
2- Fixed overwriting of finalcount in SHA1Final() (discovered by Chris Hall)
3- Changed email address from steve@edmweb.com to sreid@sea-to-sky.net

-----------------
Modified 4/01
By Saul Kravitz <Saul.Kravitz@celera.com>
Still 100% PD
Modified to run on Compaq Alpha hardware.

-----------------
Modified 07/2002
By Ralph Giles <giles@ghostscript.com>
Still 100% public domain
modified for use with stdint types, autoconf
code cleanup, removed attribution comments
switched SHA1Final() argument order for consistency
use SHA1_ prefix for public api
move public api to sha1.h

-----------------
Modified 05/2019
By DianDian Xue <ddgame3d@live.com>
Modify the style of "ddmath" project

*/

#define DDCL_CORE

#include <stdio.h>
#include <string.h>
#include <stdint.h>

#include "ddclsha1.h"

static void SHA1_Transform(uint32_t state[5], const uint8_t buffer[64]);

#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))

/* blk0() and blk() perform the initial expand. */
/* I got the idea of expanding during the round function from SSLeay */
/* FIXME: can we do this in an endian-proof way? */
#ifdef WORDS_BIGENDIAN
#define blk0(i) block.l[i]
#else
#define blk0(i) (block.l[i] = (rol(block.l[i],24)&0xFF00FF00) \
    |(rol(block.l[i],8)&0x00FF00FF))
#endif
#define blk(i) (block.l[i&15] = rol(block.l[(i+13)&15]^block.l[(i+8)&15] \
    ^block.l[(i+2)&15]^block.l[i&15],1))

/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);


/* Hash a single 512-bit block. This is the core of the algorithm. */
static void SHA1_Transform(uint32_t state[5], const uint8_t buffer[64])
{
    uint32_t a, b, c, d, e;
    typedef union {
        uint8_t c[64];
        uint32_t l[16];
    } CHAR64LONG16;
    CHAR64LONG16 block;

    memcpy(&block, buffer, 64);

    /* Copy ctx->state[] to working vars */
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];

    /* 4 rounds of 20 operations each. Loop unrolled. */
    R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
    R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
    R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
    R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
    R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
    R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
    R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
    R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
    R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
    R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
    R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
    R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
    R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
    R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
    R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
    R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
    R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
    R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
    R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
    R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);

    /* Add the working vars back into ctx.state[] */
    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
    state[4] += e;

    /* Wipe variables */
    a = b = c = d = e = 0;
}


DDCLAPI void
ddcl_init_sha1 (ddcl_SHA1Ctx * ctx){
    /* SHA1 initialization constants */
    ctx->state[0] = 0x67452301;
    ctx->state[1] = 0xEFCDAB89;
    ctx->state[2] = 0x98BADCFE;
    ctx->state[3] = 0x10325476;
    ctx->state[4] = 0xC3D2E1F0;
    ctx->count[0] = ctx->count[1] = 0;
}

DDCLAPI void
ddcl_update_sha1 (
        ddcl_SHA1Ctx * ctx,
        const dduint8 * data,
        const dduint32 len){

    size_t i, j;
#ifdef VERBOSE
    SHAPrintctx(ctx, "before");
#endif

    j = (ctx->count[0] >> 3) & 63;
    if ((ctx->count[0] += len << 3) < (len << 3)) ctx->count[1]++;
    ctx->count[1] += (len >> 29);
    if ((j + len) > 63) {
        memcpy(&ctx->buffer[j], data, (i = 64-j));
        SHA1_Transform(ctx->state, ctx->buffer);
        for ( ; i + 63 < len; i += 64) {
            SHA1_Transform(ctx->state, data + i);
        }
        j = 0;
    }
    else i = 0;
    memcpy(&ctx->buffer[j], &data[i], len - i);

#ifdef VERBOSE
    SHAPrintctx(ctx, "after ");
#endif
}

DDCLAPI void
ddcl_final_sha1 (
        ddcl_SHA1Ctx * ctx,
        dduint8 digest[DDCL_SHA1_DIGEST_SIZE]){

    uint32_t i;
    uint8_t  finalcount[8];
    for (i = 0; i < 8; i++) {
        finalcount[i] = (dduint8)((ctx->count[(i >= 4 ? 0 : 1)]
         >> ((3-(i & 3)) * 8) ) & 255);  /* Endian independent */
    }
    ddcl_update_sha1(ctx, (uint8_t *)"\200", 1);
    while ((ctx->count[0] & 504) != 448) {
        ddcl_update_sha1(ctx, (uint8_t *)"\0", 1);
    }
    ddcl_update_sha1(ctx, finalcount, 8);  /* Should cause a SHA1_Transform() */
    for (i = 0; i < DDCL_SHA1_DIGEST_SIZE; i++) {
        digest[i] = (uint8_t)
         ((ctx->state[i>>2] >> ((3-(i & 3)) * 8) ) & 255);
    }
    /* Wipe variables */
    i = 0;
    memset(ctx->buffer, 0, 64);
    memset(ctx->state, 0, 20);
    memset(ctx->count, 0, 8);
    memset(finalcount, 0, 8);   /* SWR */
}

DDCLAPI void
ddcl_tostring_sha1 (
        const dduint8 digest[DDCL_SHA1_DIGEST_SIZE],
        dduint8 str[DDCL_SHA1_STRING_SIZE]){

    for(int i = 0; i < DDCL_SHA1_DIGEST_SIZE; i++){
        sprintf(str + (i * 2), "%02x", digest[i]);
    }
}

DDCLAPI void
ddcl_hmac_sha1(const char * key, size_t key_sz,
        const char * data, size_t data_sz, dduint8 digest[]){

    ddcl_SHA1Ctx ctx;
    char keybuf[64];
    if(key_sz > 64){
        ddcl_init_sha1(&ctx);
        ddcl_update_sha1(&ctx, key, key_sz);
        ddcl_final_sha1(&ctx, keybuf);
        key_sz = DDCL_SHA1_DIGEST_SIZE;
        key = keybuf;
    }
    size_t i;
    char ipad_key[64];
    char opad_key[64];
    for(i = 0; i < key_sz; i ++){
        ipad_key[i] = 0x36 ^ key[i];
        opad_key[i] = 0x5c ^ key[i];
    }
    for(; i < 64; i ++){
        ipad_key[i] = 0x36;
        opad_key[i] = 0x5c;
    }

    ddcl_init_sha1(&ctx);
    ddcl_update_sha1(&ctx, ipad_key, 64);
    ddcl_update_sha1(&ctx, data, data_sz);
    ddcl_final_sha1(&ctx, digest);

    ddcl_init_sha1(&ctx);
    ddcl_update_sha1(&ctx, opad_key, 64);
    ddcl_update_sha1(&ctx, digest, DDCL_SHA1_DIGEST_SIZE);
    ddcl_final_sha1(&ctx, digest);
}
